I believe oSQL like most tools rely on the SQL Browser service to identify
SQL Servers. It does this by communicating with port 1434 which is the
default browser port and it will respond with the ports of any running
instances on that particular server. I believe SQL Recon does a combination
of both using the browser service and pinging particular ports looking for
SQL Server to respond. For instance if the browser service is turned off and
you ping 1434 you will get no reply. But if you have a running instance at
say the default port of 1433 and ping it specifically it will respond. If
you Google "sql server browser service" you should see a bunch of hits that
will give you a good start. This one in particular should get you going
right off the bat.
http://msdn2.microsoft.com/en-us/library/ms181087.aspx
--
Andrew J. Kelly SQL MVP
Solid Quality Mentors
"Blue Sky" <BlueSky.TakeThisOut@discussions.microsoft.com> wrote in message
news:5B49DD8D-6DA5-4684-82FE-4CD54311F18F@microsoft.com...
>I recently ran "SQLRecon" on my network and then ran SqlCmd -L. There was
>a
> 10% difference of 20 servers. (SqlCmd found more). Why wouldn't they
> both
> find the same number of servers?
>
> For years i have been connecting to Sql servers via Osql, SqlCmd,
> Management
> Studio, Query Analyzer, LinkedServers, etc. Now, i would like to
> understand
> why they might give different lists of servers back to users...
>
> My real question to the group is this: Where can i find a document that
> describes the different methods (protocols, api's) by which SqlServer
> communicates?
>
> Thanks!
>
> --
> The Spirit gives life; the flesh counts for nothing! (Jn 6:63)